Use of a soluble oil in the extraction of hydrocarbons from oil sands



9, 1968 F. H. POETTMANN ET AL 3,392,105

USE OF A SOLUBLE OIL IN THE EXTRACTION OF HYDROCARBONS FROM OIL SANDSFiled April 15. 1965 SOLVENT SOLVENT STORAGE TAR STORAGE IN VE N TORSSOLID WASTES FRED H. POETTMANN JOE T KELLY A TTORNEY/ United StatesPatent Oflice 3,392,105 Patented July 9, 1968 3,392,105 USE OF A SOLUBLEOIL IN THE EXTRACTION OF HYDROCARBONS FROM OIL SANDS Fred H. Poettmannand Joe T. Kelly, Littleton, Colo.,

assignors to Marathon Oil Company, Findlay, Ohio, a

corporation of Ohio Filed Apr. 15, 1965, Ser. No. 448,372 7 Claims. (Cl.208-11) This invention relates to the recovery of hydrocarbons and moreparticularly to the recovery of hydrocarbons from oil sands.

Such sands represent a tremendous potential reserve of hydrocarbon.Estimates of the hydrocarbon content of the McMurray formation of theAthabasca area vary between 300 and 500 billion barrels of oil. Thiscompares favorably with the current free worlds crude oil reserves of400 billion barrels. Industry has taken several steps toward therecovery of hydrocarbons from the sands. In one process, the oil sandsare contacted with steam and ammonia to reduce the viscosity of the tarsand emulsify the hydrocarbon. The emulsified hydrocarbon separates fromthe sands and is recovered. This process can be carried out either insitu or in aboveground processing plants. In another approach, bothcocurrent and countercurrent in situ combustion have been tried. Thecosts of these processes are quite high and, at the present time, thelarge scale recovery of hydrocarbons from the oil sand has not beeneffected.

US. Patent 3,057,404 teaches an in situ process wherein air, steam, anda cutting oil are injected into a subterranean formation to induceseparation of the oil from the oil sands so as to allow the sand tosettle downwardly. The separated oil is then removed.

The above method is confounded by subsidence and other problems. Thesubsidence causes bending and closure of well tubing. Soluble oils mustbe formulated which contain surfactants soluble in the crude and whichwill not precipitate from solution when contacted by ions in the crude.This is a problem in subterranean deposits as the ion content of thecrude changes from place to place.

Applicants process overcomes some of the problems inherent in the priorart processes. The amount of extractant liquid required in theextraction processes is reduced and the corrosion-resistant metals arenot needed as in the combustion processes.

Essentially, the process of this invention comprises contacting the oilsands with soluble oils, thereafter diluting the tar sand-soluble oilmixture with a solvent-diluent, and separating the sand from theresulting relatively low viscosity solution. The term soluble oil, asused in this specification and claims, refers to solutions ofsurfactants in non-polar solvents with the ability to emulsify Waterwhen admixed therewith. For purposes of this invention, the term is alsointended to include transparent emulsions. The substantially anhydroussoluble oils and transparent emulsions are well known and generallyformulated from hydrocarbons, one or more surfactants or nonsurfactantsurface-active materials, and a stabilizing agent which is usually analcohol but which may be other semipolar compounds. Several suitablesoluble oils are found in US. Patent 2,356,205. Other and preferredformulations are set out in copending US. patent application Ser. No.324,216, filed on Nov. 18, 1963, by William B. Gogarty and Russell W.Olson. Obviously, the soluble oil must be stable to the oil and water inthe oil sands and at process temperatures.

Essentially, our invention comprises a combination of separation anddilution steps which are to be carried out aboveground. In our preferredprocess, comminuted oil sands are contacted with a soluble oil to form aslurry in a mixer unit. The slurry is then mixed with a solvent-diluentand separated.

This process is more fully illustrated with reference to theaccompanying drawing where conveyer 1 passes comminuted oil sands 2 intohopper 3. Comminuted oil sands 2 pass through star feeder 4, or othersuitable valving mechanism, into slurry preparation tank 5. Soluble oilfrom storage tank 6 passes through valve 7 in line 8 toslurrypreparation tank 5 Where it is rapidly mixed with oil sands 2 bystirring devices 9. Normally, from at least about 0.1-10, and preferablyat least from about 05-15, volumes of soluble oil per volume of oil sandproduce a desired slurry. A mixture of four parts tar sand and one partof a soluble oil comprising straight run gasoline, isopropanol (about 4%and water (about 25%) creates a loose slurry on mixing. After a slurryof suitable viscosity, preferably from about 500 to about 50,000 cps.,is prepared, it passes through valve 10 into dilution tank 11 Where itis mixed with solvent. Solvent from solvent storage 12 passes throughvalve 13 in line 14 into dilution tank 11 where it serves to furtherreduce the viscosity of the slurry. A mixture of four parts of the aboveloose slurry and one part straight run gasoline gives a solution whichappears to have a viscosity approximating that of kerosene. Normally,from at least about 0.515 volumes of solvent are added per volume ofslurry. The amount of solvent added depends upon the viscosity of thesolvent, the temperature of the solvent and the slurry, etc. Solventssuch as straight run gasoline, liquefied petroleum gases, xylene,isopropanol, dimethyl-formamide, furfural, phenol, etc., andcombinations thereof, can be used in this process. When diluted to adesired degree, for example, from about 30 to about 1000 cps., thediluted mixtures pass through valve 15 into separator 16. Separator 16is depicted as a cyclone separator but can be any desired liquidsolidseparator. On separation, the sand and other solid wastes pass throughvalve 17 to a waste disposal means. The liquids pass from separator 16through line 18 into distillation tower 19 where the light, low-boilingsolvent is distilled from the mixture. The solvent is then recycledthrough line 20 to solvent storage 12. The bituminous bottoms are thenremoved to storage tank 1. From storage, the bituminous materials aretransported to market, etc.

Temperatures, for example, up to from about 30 to about C., can aid inthe desired separation. The use of heat, of course, would depend on itsavailability, solvent, soluble oil, etc., costs and the like. Theoptimum viscosities outlined as useful at various stages in the processwill vary with the equipment and temperatures used in carrying out theprocess.

In a preferred embodiment of the above invention, a soluble oil whichtakes up water only poorly can be used to advantage. Such soluble oilsare, of course, miscible with the oil from the oil sands. In thisparticular embodiment, large amounts of steam can be introduced into thesolvent oil-oil sands mixture to effect the desired reduction in theviscosity of the mixture so as to aid in separating sands from themixture. To further aid in the formation of the desired slurry, the oilsands can be preheated.

Now having described our invention, what we claim is:

1. The process for recovering oil from tar sand comprising contacting,in a mixing unit, a substantially solid tar sand with a soluble oil toform a mixture of tar, sand, and soluble oil; contacting the saidmixture with sufiicient diluent fluid to form a lower viscositysolution; and separating the sand therefrom.

2. The process for recovering oil from tar sands comprising contacting,in a mixing unit, sized lumps of substantially solid tar sands with atleast about 0.1-10 volumes of soluble oil per volume of tar sand to forma mixture of tar, sand, and soluble oil; contacting the said mixturewith at least about 05-15 volumes of diluent fluid per volume of saidmixture to form a relatively low viscosity solution of tar and diluent;and separating the sand therefrom. 7

3. The process for recovering oil from tar sands comprising agitating,in a mixing unit, a substantially solid tar sand with at least about0.5l5 volumes of soluble oil per volume of tar sands to form a mixtureof tar, sand, and soluble oil having a viscosity of from about 500 toabout 50,000 cps.; contacting the said mixture with sufficient diluentfluid to form a relatively lower viscosity solution of tar and diluentand soluble oil; and separating the sand therefrom.

4. The process for recovering oil from tar sands comprising agitating,in a mixing unit, a substantially solid tar sand with at least about0.515 volumes of soluble oil per volume of tar sand to form a mixture oftar, sand, and soluble oil having a viscosity of from about 500 to about50,000 cps; contacting the said mixture with at least about 0.515volumes of diluent fluid per volume of said mixture to form a mixturehaving a viscosity of from about 30 to about 1000 cps. at operatingtemperatures; and separating the sand therefrom.

5. The process for the recovery of oil from tar sands comprisingcontacting, in a mixing unit, sized substantially solid tar sandparticles with a soluble oil to form a mixture of tar, sand, and solubleoil; contacting the said mixture with suflicient diluent fluid to form arelatively lower viscosity mixture; separating the sand from therelatively low viscosity mixture to form a substantially solidfreesolution; separating the diluent fluid from the substantially solid-freesolution; and contacting additional amounts of said tar, sand, andsoluble oil mixture with the separated diluent fluid.

6. The process for recovering oil from tar sands com- 4 solid tar sandparticles with at least about 0.1-10 volume of soluble oil per volume oftar sand to form a mixture of tar, sand, and soluble oil; agitating thesaid mixture with at least about 0.5-15 volumes of a diluent fluid pervolume of said mixture to form a relatively lower viscosity liquidsolidmixture; separating the sand therefrom to form a substantially solidsfree liquid isolution; separating the diluent fluid from said solidsfree liquid solution; and contacting additional amounts of said tar,sand, and soluble oil mixture with the separated diluent fluid.

7. The process for recovering oil from tar sands comprising contacting,in a mixing unit, a substantially solid tar sand with at least about0.515 volumes of soluble oil per volume of tar sands to form a mixtureof tar, sand, and soluble oil having a viscosity of from about 500 toabout 50,000 cps; contacting the said mixture with at least about 05-15volumes of diluent fluid per volume of said mixture to form aliquid-solid mixture having a viscosity of about 301000 cps. atoperating temperatures; separating the sand from said liquid-solidmixture to form a substantially solids free liquid solution; separatingthe diluent fluid from said solids free liquid solution; and contactingadditional amounts of said tar, sand, and soluble oil mixture with theseparated diluent fluid.

References Cited UNITED STATES PATENTS 3,050,289 8/1962 Gerner 2081l3,082,822 3/1963 Holm et al. 166-9 3,126,952 3/1964 Jones 166-93,163,214 12/1964 Csaszar 2528.55

DANIEL E. WYMAN, Primary Examiner.

P. E. KONOPKA, Assistant Examiner.

1. THE PROCESS FOR RECOVERING OIL FROM TAR SAND COMPRISING CONTACTING,IN A MIXING UNIT, A SUBSTANTIALLY SOLID TAR SAND WITH A SOLUBLE OIL TOFORM A MIXTURE OF TAR, SAND, AND SOLUBLE OIL; CONTACTING THE SAIDMIXTURE WITH SUFFICIENT DILUENT FLUID TO FORM A LOWER VISCOSITYSOLUTION; AND SEPARATING THE SAND THEREFROM.